iOS 12.1.3 (build 16D40) is an official Apple over-the-air update for the iPhone XS, released on 2019-01-22T18:15:01Z. The update package is 389.33 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c0e1ec0a1583d1bb1781cbcca1c1b5a90a7354a6.zip.